Marine Life of the Dampier Archipelago - WA Museum / Woodside

Researchers: BlueNet Data Faciliatator (Processor of) ,  Strong, Morgan (Point of contact)

Brief description Between 1998 and 2000 a partnership between the Western Australian Museum and Woodside Energy Ltd. was formed to survey and collect the marine flora and fauna of the Dampier Archipelago. Techniques employed during the surveys of the Dampier Archipelago included SCUBA diving, shore collecting, dredging, underwater photography of living specimens and video recording of the ocean floor, which resulted in the recording of more than 4 500 species, including 268 new to science. Many publications resulted from this survey and a website was created to distribute this valuable information.

Lineage Maintenance and Update Frequency: notPlanned

Lineage Statement: The two diving expeditions (DAI/98 and DA3/99) and the dredging expedition (DA2/99) conducted surveys of a selected marine biota of the Dampier Archipelago, from the support vessels Kimberley Quest, Top Gun II and the Fisheries Research Vessel Flinders, respectively. The selection of the groups of organisms studied was based mainly on two factors, the scientific expertise available and the ecological significance of the organisms in the Dampier Archipelago. The groups of organisms selected for study were as follows: 1) marine algae, 2) sponges, 3) hard corals, 4)crustaceans, 5) molluscs, 6) echinoderms and 6) fishes. Marine reptiles, snakes and mammals were not included in the current survey.

Lineage Statement: - Diving Expeditions (DA1/98 and DA3/99) - Areas surveyed by diving expeditions Stations were located throughout and seaward of the islands of the Dampier Archipelago and provided extensive sampling of a variety of shallow water habitats. Samples were obtained from a total of 70 stations, from the intertidal to depths of 27 m (DA3/99) and 30 m (DA1/98), respectively. Thirty-five stations in the Burrup Peninsula area were visited by the DA1/98 expedition, all but two being to the north of Searipple Passage. The DA3/99 expedition sampled 35 stations in the area west of the Burrup Peninsula. For completeness, selected stations visited during the diving expedition DA4/00, which was associated with the international marine biological workshop held in 2000, are listed on the website and report. The stations were located in a range of habitats, ranging from intertidal flats exposed at low water to deeper subtidal waters adjoining off-shore islands and shoals. Selection of stations showing potential for survey was made prior to the commencement of the expeditions. Coloured aerial photographs were viewed using a stereoscope and stations chosen to provide the best coverage of the region's marine environment. Two major marine habitats were identified - hard bottoms and soft bottoms. These were further divided into intertidal and subtidal stations.

Lineage Statement: - Diving survey methodology - The major aim of the survey of the Dampier Archipelago is to document the species diversity of its marine biota. Two different methodologies were adopted for the diving surveys. The first involved SCUBA diving, plus some snorkelling, to collect and record the biota in subtidal regions, whereas the second was based on intertidal shore collecting during periods of extreme low water. The former was used extensively to survey the different habitats that surround the islands of the study area, whereas the latter was employed opportunistically when suitable conditions were present (mostly in the early morning or late afternoon). - SCUBA diving - The goal of this work was to discover the species inhabiting each of the selected stations. Although efforts were made to maximise species lists during the one hour dive period, part of the time was devoted to sampling and video taping along are determined transect for later analysis (description below). Each of the subtidal stations (DA1/98 24 stations, DA3/99 26 stations) usually represented several different habitat types (e.g. limestone slope with coral reef, fronted by bare limestone pavement with sandy patches). Where possible, all were visited and the inhabitants either recorded on underwater slates (where identifications were considered unequivocal) or collected (some difficult to identify groups require extensive sampling). Much of the latter material was photographed, often underwater before collection, but also after removal to the support vessel; it was then processed and stored in preservative for the return trip to Perth.

Lineage Statement: - Video recorded transects - Subtidal sampling stations were surveyed during 1998 and 1999 diving expeditions (DA1/98 and DA3/99). Video recordings of each of 45 subtidal stations (19 by DA1/98; 26 in triplicate by DA3/99) were acquired by movement of a housed Sony CCD Handycam Video 8 camera along a 25.0 m transect (Carleton and Done, 1995). Each transect was marked by lying a 25.0 m measuring tape along the substrate of relatively uniform depth. A diver maintained a constant speed of 0.2m/sec. and the video was kept approximately 0.5 m above the surface of the biota. This captured a bandwidth of around 0.6 m and a total area of 15.0 m2 per transect. During the first diving expedition (DA1/ 98), replicate transects were not undertaken but replicate transects were undertaken during the second diving expedition (DA3/99). Video recording was captured electronically, saved to file and then stored on compact disc. The Sinclair Knight Merz Pty. Ltd. Video Transect Analysis System then retrieved the electronically recorded transect for analysis. The program randomly selected 200 frames, each allocated with one randomly placed spot. Benthic categories were assigned to the substrate type beneath the respective spots. Since much of the benthic fauna present along the transects was cryptic or had not been described taxonomically, the benthos was identified to functional group level. The benthic categories were comprised of the following: - three abiotic categories (sand, rubble and rock); - macroalgae; - three soft coral categories (alcyoniids, nephtheids and gorgonians); - eight coral categories (branching Acropora, corymbose Acropora, digitate Acropora, encrusting non-Acropora, massive non-Acropora and mushroom coral); and - six additional categories (sponge, anemone, mollusc, echinoderm, ascidian and other). Once benthic categories were assigned and the respective frame completed, the program advanced along the transect to the next randomly selected frame and this process was repeated until the 200 frames were completed. Upon completion, the program computed percentage cover of the habitat by each benthic category.

Lineage Statement: - Shore collecting - Expedition members were ferried ashore by dinghy just prior to low water (DA1/98 13 occasions, DA3/99 nine occasions). After landing, members searched the surrounding area for material relevant to their particular animal or marine plant group. Rock and rock pools that were normally submerged during mid and high water were especially targeted (many animals hide under rocks or gather in pools as the tide drops). Exposed tidal flats and the mangroves behind them were also investigated for burrowing animals. Much of this material was photographed in situ. The time spent at a shore station was generally two hours, after which the team returned to the support vessel to process and preserve the collections. Preserved specimens were identified by taxonomic specialists in Australia and other countries for identification to species level.

Lineage Statement: - Dredging Expedition DA2/99 - Areas surveyed by dredging expedition A total of 100 stations was sampled in shallow water between depths of 7 - 43 m. Extensive sampling of a variety of habitats was made throughout and seaward of the islands of the Dampier Archipelago. Less extensive sampling was made in and seaward of Nickol Bay, Delambre, Haüy and Legendre Islands. - Dredging survey methodology - The dredging survey was designed to obtain samples of fauna that could be identified to species. The dredge type was a rake box dredge, mouth area 1200 cm x 330 cm, with a 1.0 cm mesh. Except when interrupted by snagging, the dredge was towed at 2-3 knots for 10 mins duration. For some stations (i.e. DA2/99/2a, 44, 80, 86, 92-96 and 100), a sleeve of flyscreen was inserted into a shovel box dredge to recover smaller fauna. Ninety-seven stations were sampled by dredging and three stations (DA2/99/11, 14 and 97) were sampled with a benthic grab for infaunal and sediment analysis. Rake box dredge samples were obtained from depths between 7.0-43.0 m, shovel box dredge samples from 5.0-39.0 m and benthic grab samples from 9.5-38.0 m. Dredging samples, including sediment, sponges, rock, etc., were washed through sieves and specimens were sorted at sea into major taxonomic groups (e.g. sponges, molluscs, sea fans, etc.). Preserved specimens were identified by taxonomic specialists in Australia and other countries for identification to species level.

Lineage Statement: - GIS Spatial Datasets - Video-transects and GPS co-ordinates of sampling stations ensure that collected base-line data are permanent temporal records. Metadata and GIS spatial datasets were formalised from these data, including species lists of all faunal and floral taxa collected, by professional collaboration between the Western Australian Museum, Woodside Energy Ltd., the Western Australian Department of Fisheries, the North West Shelf Joint Environmental Management Study, (Western Australian Department of Environmental Protection), the Marine Conservation Branch, Western Australian Department of Conservation and Land Management and Sinclair Knight Merz Pty. Ltd.. Seventy eight video transects, which correspond to locations within the DA1/98/DA3/99 diving location dataset, accompany the GIS spatial datasets. These data are essential for future industrial and port development and conservation and management of biodiversity in the Dampier Archipelago. Metadata and GIS spatial datasets are available on request from the Western Australian Museum, Perth.

Notes Credit
A joint project with Woodside Energy Ltd. who provided funding

Notes Purpose
The project had several key goals; - To survey the biodiversity in the waters of the Dampier Archipelago and to generate a list of species recorded; - To collect fauna from the Dampier Archipelago, to be held in the Woodside Collection at the Western Australian Museum; - To liaise with stakeholders in the Dampier Archipelago regarding conservation of the marine biodiversity in the area; - To provide information that would assist in the conservation of the marine biodiversity in the Dampier Archipelago and its waters; and - To present the information gained from the research to the public, both in Western Australia and worldwide

Data time period: 1998 to 2000

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116.65,-20.525

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